In a papermaking machine, the fabric that supports the paper web is conditioned by passing the fabric beneath high pressure water showers or jets. The water shower, which is generally operating at a pressure of about 400 psi, has a diameter of about 0.040 inch and acts to clean the fabric as well as redistributing the fibers.
In some situations, a series of showers are mounted transversely across the path of travel of the fabric, while in other situations one or more showers may move in a reciprocating path across a portion of the width of the fabric. The showers also provide the desired moisture profile across the width of the fabric.
The pressure of the water being discharged from the nozzles is initially calculated from the pressure of the water in the main and the diameter of the nozzle. However, during use, the nozzle orifice may be enlarged through wear or erosion, or the nozzle size may be decreased by virtue of clogging. In addition, the main pressure may vary considerably from the original pressure. Because of this, it has been found that the pressure in the nozzles may vary considerably from the original or desired pressure. If the pressure is too low, the cleaning and conditioning action will be less effective, while if the pressure is too high, the fibrous material can be damaged or displaced.
Because of the high pressure of the water being discharged from the nozzles, a pressure gauge cannot be manually held in the jet stream without considerable movement of the gauge making readings unreliable. Therefore, there has been a need for a manually operated gauge which will accurately measure the high pressure discharge of the spray nozzles.